注射LHRHa对泥鳅血清性类固醇激素变化研究

研究了注射促黄体激素类似物(LHRHa)后,泥鳅(Misgurnus anguillicaudatus)血清性类同醇激素的变化规律,并探讨在泥鳅繁殖季节时.孕酮(P)、睾酮(T)和雌二醇(E2)对性腺发育的作用及调节机制.实验共分两组,对照组和实验组;对照组只注射生理盐水;实验组注射LHRHa,雌鱼0.2 μg/g,雄鱼减半.注射前尾静脉采血,作为血液样本分析基础水平(Oh),注射药物后分别在7、24、48、72和96h尾静脉采血.测定雌鱼睾酮、雌二醇和孕酮,雄鱼孕酮和睾酬血清浓度.实验结果表明:注射LHRHa,雌鱼血清睾酮和雌二醇浓度显著高于对照组,雄鱼血清睾酮和孕酮显著高于对照组(P<0.05);24h浓度较高.雌鱼孕酬、睾酮和雌二醇分别为(0.710±0.082)ng/mL、(9.00±0.57)ng/mL和(696.4±26.2)pg/mL,雄鱼孕酮和睾酮分别为(0.527±0.121)ng/mL和(9.62±0.62)ng/mL.实验组雌鱼孕酮变化基本规律为,基础水平(0-7h)-逐渐升至最高(7-24h)-逐渐降至基础水平(24-48h)-维持基础水平(48-96h).实验组雌鱼睾酮和雌二醇与雄鱼孕酮和睾酮变化规律基本相似,其规律为,逐渐上升至最高(0-24h)-逐渐降至基础水平(24-72h)-维持基础水(72-96h).24h对照组雌鱼睾酮和雌二醇显著升高,浓度分别为:睾酮(2.20±0.18)ng/mL,雌二醇(269.1±36.6)pg/mL.对照组雄鱼血清孕酮和睾酮浓度实验期间均无显著变化.研究认为:LHRHa能够刺激泥鳅性类同醇激素分泌,特别是睾酮的分泌,显著提高雌鱼性腺指数(GSI).但刺激P的分泌调控能力有限,实验期间处于较低水平,诱导排卵效果差,泥鳅的性类固醇激素可能有特殊的调节机制.雌二醇和睾酮对性腺成熟有重要作用,孕酮对介导卵细胞最终成熟和排卵可能起重要作用,而雌二醇和睾酮无明显效果.

Change discipline of sex steroid hormones in serum of loach (Misgurnus anguillicaudatus) Infected chorionic gonadotropin analogue(LHRHa)

This experiment was to clarify the change of sex steroid hormone in serum of loach (Misgurnus anguillicauda-tus) infected LHRHa, and investigate actions of progesterone (P) , testosterone (T) and estradiol (E_2) to gonadal development and regulatory mechanism. It contented two groups, control group and test group. The fish of control group were only injected physiological saline, and the fish of test group were injected chorionic gonadotropin analogue D-Ser( tBu)6, Pro9-NEt] ( LHRHa) (female fish 0.2ug/g and male fish 0. lug/g). Blood samples were collected from caudal vein at 0, 7, 24, 48, 72 and 96h after implantation respectively, and T, E_2 and P contents in serum were measured. These results showed that T and E_2 in serum of female fish infected LHRHa were significantly higher than those of control group (P < 0.05). 24h after infection LHRHa, P, T and E_2 contents of female fish were 0.710±0.082ng/mL, 9.00±0.57ng/mL and 696.4±26.2pg/mL respectively; P and T of male fish were 0.527±0.121ng/mL and 9. 62±0.62ng/mL respectively. Change discipline of female fish in test group was as following rule, basis level (0-7h)-to rise gradually to the peak value (7-24h) to go down to basis level (24-48h) to maintain basis level (48-96h). The change discipline of T and E_2in female fish and P and T in male fish were similar, to rise gradually to the peak value (0-24h) to go down gradually to basis level (24-48h) to maintain basis level (48-96h). After 24h, the T and E_2 contents of female fish in control group been significantly hoisted to 2.20+0.18ng/mL and 269.1+36.6pg /mL, but the P and T contents of male fish in control group changed unobviously ( P > 0.05). The experimental results indicated that LHRHa could stimulate sex steroid hormone secretion of loach to female loach, especially T, and raised significantly the gonadosomatic index (GSI) , but it had poor effect to induce ovulation. The reason may be that it had especial regulatory mechanism of steroid hormone. E_2 and T in loach could promote sex gland maturity. P may play important role in final maturity of oocyte and ovulation in loach, and E_2 and T had no obvious action in this way.